display all the ideas for this combination of texts
3 ideas
9718 | Validity is either semantic (what preserves truth), or proof-theoretic (following procedures) [Enderton] |
10893 | Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo] |
10899 | Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo] |